1. Field of the Invention
The present invention relates to a personal authentication apparatus.
2. Description of the Related Art
Methods for personal authentication are broadly classified into three categories. One is authentication based on possessions such as a key and an ID card (for example, see Japanese Patent Laid-Open Publication No. Hei 6-155971). The possession-based authentication, however, is under security threats ascribable to loss and theft. Another is authentication by knowledge such as a password. Nevertheless, the knowledge-based authentication also has security problems due to oblivion, undertook, etc. The other authentication method which has been attracting attention in recent years is biological authentication using biological information such as fingerprints, palm prints, faces, irises, and voice prints. The biological authentication considerably suppresses the security threats ascribable to “loss” which can occur in the foregoing possession- and knowledge-based authentications. In addition, since the users “need not possess” any object or knowledge, it is easy to provide an authentication system of high convenience.
Because of these advantages, personal authentication apparatuses based on biological information are expected to replace the authentication based on possessions such as a house key and a car key. Recent years have seen the emergence of active e-commerce, which often uses knowledge-based authentication methods. Even in this field, authentication apparatuses of higher convenience and safety have been awaited.
In the personal authentication based on biological information, it is necessary to detect features of personal biological information with high precision. Personal authentication by such biological information as a fingerprint and a palm print are how becoming available with relatively high accuracies of authentication. Nevertheless, the sensors of the authentication apparatuses tend to be unsanitary, being touched by an unspecified number of users. The authentication methods using irises and retinas also have the same problem because the users bring their faces as close to the authentication apparatuses as almost into touch with. On this account, many users have psychological resistance more or less against the personal authentication apparatuses that acquire biological information by contact or such means (hereinafter, referred to collectively as “contact-type personal authentication apparatuses”). In particular, fingerprints have long been used in criminal investigations by the police. This historical background makes users liable to avoid the personal authentication based on fingerprints. As described above, contact-type personal authentication apparatuses are generally poor in acceptability.
On the other hand, personal authentication apparatuses based on facial authentication are highly acceptable since the biological information can be acquired even if the users are not in contact with the apparatuses. The facial authentication and other noncontact-type personal authentication apparatuses are, however, poor in the accuracy of authentication as compared to the contact-type personal authentication apparatuses. Thus, the noncontact-type apparatuses are typically used as auxiliary means in combination with other authentication methods.
Related Art List
JPA laid open Publication No. Hei 6-155971